Autofocus with Nikon D3000 AF Nikkor 50mm lens?

I just got a new 50mm lens for my Nikon D3000 camera, but for some reason it will not autofocus. The lens I got that comes with the D3000 camera has a switch to set autofocus and manual focus, but this 50mm lens doesn't have that switch. I've been trying to read up on it and people are saying that the lens has to be AF-S, not AF, in order to autofocus with the Nikon D3000. If this is so, does that mean I'm stuck using manual focus? The lens says "Nikon AF Nikkor." I also tried going to the menu and toggling the AF area mode setting but I get the message "this option is not available with current settings." So is there, alternately, a way to change settings on the camera so that I can toggle the AF area mode setting? I'm not sure what settings to change in order for that message to go away!

You have the same 50mm Nikon AF lens that I have for my D300. But for entry level Nikon dslr's to autofocus, you need an AF-S lens like the newest 50mm that came out last year.
http://www.kenrockwell.com/...-f18-g.htm

Your camera requires a built-in autofocus motor in the lenses for full functionality. Here's a website that shows the latest lens that perfectly match your D3000.
http://en.wikipedia.org/...cus_motors

Unfortunately, Nikon decided to cripple all their lower-level DSLRs like the D3000, D3100, D5000 and D5100 by omitting a focusing motor in those camera bodies. What this means is that if you want auto focus you must buy the more expensive AF-S lenses. The AF-S 50mm f1.8 will cost you about $90.00 more than the AF 50mm f1.8 lens. Great for Nikon but not so much for you. So either learn to focus manually or pay the extra $90.00 and get the AF-S 50mm f1.8 lens.

Sony and Pentax DSLR cameras all have a focusing motor in their DSLR camera bodies.